Industry is the production of a good or service within an economy. Manufacturing industry became a key sector of production and labour in European and North American countries during the Industrial Revolution, upsetting previous mercantile and feudal economies. This occurred through many successive rapid advances in technology, such as the production of steel and coal.
Following the Industrial Revolution, perhaps a third of the world's economic output is derived from manufacturing industries. Many developed countries and many developing/semi-developed countries (People's Republic of China, India etc.) depend significantly on manufacturing industry. Industries, the countries they reside in, and the economies of those countries are interlinked in a complex web of interdependence.
The industrial revolution led to the development of factories for large-scale production; with consequent changes in society. Originally the factories were steam-powered, but later transitioned to electricity once an electrical grid was developed. The mechanised assembly line was introduced to assemble parts in a repeatable fashion, with individual workers performing specific steps during the process. This led to significant increases in efficiency, lowering the cost of the end process. Later automation was increasingly used to replace human operators. This process has accelerated with the development of the computer and the robot.
Industry is the one of the largest energy consumers, considering the other sectors like commercial and domestic sectors. Main energy sources used by industries are; electricity, petroleum fuel oils, coal, gases etc.
Followings describe about the high energy consuming sectors and energy conservation opportunities in them. Thermal storage systems and Tri-generation are some advance technological concepts utilised to capture the waste heat or use the low cost energy at off peak time, and consequently improve the efficiency paving the way for energy conservation.